Overdrive off button flashes and speedo not working

[mick883]

It is not happening all the time but...

My overdrive button flashes. When that is happening, I notice that my speedometer is not working. I pull over shut the truck off, restart and everything works fine.

Any ideas?

PS. my ABS light has been coming on randomly and I believe that my rear sensor is going .

I don't think the two are related but I wanted to mention it.

[CHUCK]

The od light flashing... the trans has set a code. The speed sensor on the rear end is bad. 99% sure,When the sensor is replaced, should clear up all problems, od light flashing/spedo not working /and the abs light.

[Jarrod B]

just go to some tranny shop for a free test to pull codes

[mick883]

Thanks.
Any other ideas/advice/opinions is always appreciated.

[layson]

yep... speed sensor. There are also two in the front. Each ABS sensor in the hubs is a speed sensor. But probably the one in the rear...

[mick883]

so is the speed sensor and the abs sensor two different things?

I imagine they are. I was planning on getting an ABS sensor for the rear from Advanced Auto (on $17). Should I still replace that or should I change the speed sensor first to see if it fixes everything. OR is the ABS and speed sensor all in one unit??

[layson]

The abs sensor in each front hub is a speed sensor. The computer takes input from each hub and the rear diff. then I think there is another sensor or two in the tranny.

You can pull the codes to find which one is bad. If someone nearby has AE software or a good code reader they can tell which one is bad...